Malicious PDF — malware analysis report

Static analysis result for SHA-256 903053cbc134511a…

MALICIOUS

PDF

71.3 KB Created: 2021-10-02 12:04:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 0de200ff25a5a5a31135728fb375929f SHA-1: 51d64b97c1a69befc48f0727170f60c98328cd8d SHA-256: 903053cbc134511abe1bddc7597a6cf77c63c84abde7b374d1a6800e3a5fe531
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains numerous embedded URLs that point to external websites, many of which are hosted on potentially compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The structure suggests a link farm designed to obscure the final destination and evade basic detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://uclerbaklava.com/resources/file/65511984027.pdf In PDF document text
    • https://bunian-co.com/other_files/File/xiribet.pdfIn PDF document text
    • https://kamhosting.nl/ckfinder/userfiles/files/pisugepetomubidawupi.pdfIn PDF document text
    • http://flightshop.jp/images/blog/file/13827230796.pdfIn PDF document text
    • http://xinxinhouseware.com/uploadfile/files/42602581983.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/pifekokadudowipopomuve.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/93325670727.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109270600518282.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/72rg373v7tsi5jc20ockmeh674/35538644721.pdfIn PDF document text
    • https://rocha.pt/userfiles/file/34508879916.pdfIn PDF document text
    • http://yacpa.org/yacpafiles/file/25118303588.pdfIn PDF document text
    • http://air-ned.com/uploads/files/30045913656.pdfIn PDF document text
    • http://yourmoneyyourbank.com/uploads/File/ditaterutenebubanuzej.pdfIn PDF document text
    • http://kezmosas.hu/files/file/bojerapam.pdfIn PDF document text
    • http://fteq.ru/files/file/bagabanivuxafinodidevate.pdfIn PDF document text
    • http://dkkarsin.pl/img/upload/files/9035815647.pdfIn PDF document text
    • http://splogservice.ru/content/files/58063742442.pdfIn PDF document text
    • https://www.andimoda.com/wp-content/plugins/super-forms/uploads/php/files/a78b3b50e9d3cff272da1f26eeeaaae7/40984181300.pdfIn PDF document text
    • http://discus-rus.ru/upl/file/kapekurevasamiruxidavi.pdfIn PDF document text
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/a01d40a01607ee48aee6869afa12616c/tekubu.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/28884149082.pdfIn PDF document text
    • http://www.radeton-cz.vasestranky.cz/ckfinder/userfiles/files/51556817305.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=do+you+wash+dark+clothes+in+cold+waterPDF link annotation
    • https://tes-sys.com/uploads/ckfinder/files/20210906/16308823978794.pdfIn PDF document text
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b3d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3D1 16472 bytes
SHA-256: a4478a3956b74f51e256915436aa6b03b97029919fce5e28640506863346861c
font_01_sfnt_off0000de01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE01 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f618.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF618 10860 bytes
SHA-256: d9c9270f6333fab2e8e80613054816d82cb1cdf1c4f901f51187e7db9ec8dd17